Multicarrier Equalization: Unification and Evaluation. Part II: Implementation Issues and Performance Comparisons

Equalization is crucial in mitigating inter-carrier and inter-symbol interference in a multicarrier system. To ease equalization, typically a cyclic prefix (CP) is inserted between successive symbols. When the channel order exceeds the CP length, equalization can be accomplished by placing a timedomain equalizer (TEQ), in the form of a finite impulse response (FIR) filter, in cascade with the channel. The TEQ is designed to produce a shortened effective impulse response. Alternatively, a bank of equalizers can be used to remove the interference tone-by-tone. A literature survey and a unified treatment of optimal equalizer designs for multicarrier receivers were presented in Part I of this paper. This Part II focuses on implementation and performance issues. Complexity reduction techniques are discussed, and the computational complexity of these techniques is tabulated. In addition, 16 different equalizer structures and design procedures are compared in terms of achievable bit rate using synthetic and measured data.